Technique of Percutaneous Nephrolithotomy

What is the safe and effective dilator number during access in PCNL? Three-shot dilation versus classical sequential Amplatz dilation

BACKGROUND

Although PCNL has been used for a long time to treat nephrolithiasis, there is still contradictory information concerning the use of the dilation method. In this study, we aimed to compare conventional sequential Amplatz dilatation (SAD) using ten dilators and a method using three dilators (12, 20, and 30 Fr), which we named "three-shot dilatation" (3SD), in terms of fluoroscopy time (FT), operation time, bleeding and stone-free rates.

METHODS

The study included patients who underwent PCNL with the SAD and 3SD methods. A different surgeon with extensive endourology experience applied each technique. One of the surgeons operated on the patients using the SAD method with ten dilators, and the other surgeon performed the operations using the 3SD method involving three Amplatz dilators (12, 20, and 30 Fr).

RESULTS

A total of 283 patients, 138 in the 3SD group and 145 in the SAD group, were included in the study. The mean age of the patients was 47.32 ± 13.71 years. There was no statistically significant difference between the two groups regarding preoperative characteristics (p > 0.05). The FTs of access 2, total access, and total operation were significantly shorter in the 3SD group (p = 0.0001). The decrease in hemoglobin was statistically significant in the 3SD group compared to the SAD group (p = 0.022), while the blood transfusion requirements of the groups were similar (p = 0.176). There was no statistically significant difference between the two groups regarding stone-free rates (p = 0.973). In four patients in the SAD group, re-access was necessary due to the loss of passage due to the guide wire slipping out of its place.

CONCLUSION

Intraoperative FT can be shortened using the described 3SD method without compromising surgical safety. However, this method can be used as an intermediate step in the transition to one-shot dilation by surgeons experienced in performing SAD.

Comparison of Contrast-Enhanced Ultrasound vs Conventional Ultrasound-Guided Percutaneous Nephrolithotomy in Nondilated Collecting System: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: It has been demonstrated that ultrasound (US)-guided renal collecting system access during percutaneous nephrolithotomy (PCNL) is efficient and secure. The puncture success rate fell to 82%, and the total complication rate rose to 15% in kidneys with nondilated collecting systems. Contrast-enhanced ultrasonography (CEUS) has been used in PCNL techniques to address this issue. Methods: We did this meta-analysis following the preferred reporting criteria for systematic reviews and meta-analysis to combine the data of published studies to compare the CEUS-guided PCNL and the standard US-guided PCNL (PRISMA). For relevant literature, we searched PubMed, Embase, Web of Science, CKNI, and the Cochrane Library. The final inclusion date for this meta-analysis was May 1, 2022, and three randomized controlled trials (RCTs) were finally included. RevMan V5.4.1 was used in this work. Standard mean difference (SMD) with a 95% confidence interval (CI) was utilized as the major estimate in the synthesis of continuous data, while odds ratio (OR) with a 95% CI was synthesized as the main estimate in the synthesis of discontinuous data. Results: We found that compared with traditional US-guided PCNL, CEUS-guided PCNL could offer more benefits in terms of single-needle success rate (OR: 3.02, 95% CI: 1.62 to 5.61, p = 0.0005), shorter puncture time (SMD: -1.33, 95% CI: -2.06 to -0.60, p = 0.0004), shorter hospital stays (SMD: -0.37, 95% CI: -0.60 to -0.13, p = 0.002), and a better stone clearance rate (OR: 2.32, 95% CI: 1.15 to 4.68. p = 0.02). Although the PCNL complication rate after surgery was not significantly reduced by the CEUS technique (overall complication: OR = 0.70, 95% CI: 0.37 to 1.30, p = 0.25. Grade 1/2 complication: OR = 0.79, 95% CI: 0.41 to 1.53, p = 0.48; Grade 3/4 complication: OR = 0.44, 95% CI: 0.10 to 1.98, p = 0.28), it could reduce hemoglobin dropping compared with conventional US-guided PCNL (SMD: -0.82, 95% CI: -1.06 to -0.58, p < 0.001). Conclusion: The CEUS-guided PCNL technique is superior to the US-guided PCNL, according to almost all synthesized data. Additional randomized studies are still required.

Retroperitoneal laparoscopic renorrhaphy for post-percutaneous nephrolithotomy hemorrhage: a case report

Percutaneous nephrolithotomy is the preferred treatment for large renal calculi; however, postoperative hemorrhage is a dangerous complication. The three main causes of hemorrhage after percutaneous nephrolithotomy are pseudoaneurysms, arteriovenous fistulas, and arterial lacerations. The preferred treatment for acute hemorrhage is superselective angioembolization. However, in a few cases, angiography reveals no abnormal findings pertaining to hemorrhage. We herein present a clinical case of a 48-year-old man who presented with multiple complex right renal calculi and was managed with percutaneous nephrolithotomy in the prone position. Massive hemorrhage occurred 6 days postoperatively, and renal angiography was immediately performed. However, while the bleeding was still occurring, no extravasation was observed on renal angiography. We performed retroperitoneal laparoscopic renorrhaphy, which successfully stopped the bleeding and consequently preserved the kidney. We suggest that retroperitoneal laparoscopic renorrhaphy can be effective in patients who have undergone failed renal arterial embolization or are reluctant to undergo renal arterial embolization.

Validity of a patient-specific percutaneous nephrolithotomy (PCNL) simulated surgical rehearsal platform: impact on patient and surgical outcomes

INTRODUCTION

Simulators provide a safe method for improving surgical skills without the associated patient risks. Advances in rapid prototyping technology have permitted the reconstruction of patient imaging into patient-specific surgical simulations that require advanced expertise, potentially continuing the learning curve.

OBJECTIVES

To evaluate the impact of preoperative high-fidelity patient-specific percutaneous nephrolithotomy hydrogel simulations on surgical and patient outcomes.

MATERIALS AND METHODS

Between 2016 and 2017, a fellowship-trained endourologist performed 20 consecutive percutaneous nephrolithotomy procedures at an academic referral center. For the first ten patients, only standard review of patient imaging was completed. For the next ten patients, patient imaging was utilized to fabricate patient-specific models including pelvicalyceal system, kidney, stone, and relevant adjacent structures from hydrogel. The models were tested to confirm anatomic accuracy and material properties similar to live tissue. Full procedural rehearsals were completed 24-48 h before the real case. Surgical metrics and patient outcomes from both groups (rehearsal vs. standard) were compared.

RESULTS

Significant improvements in mean fluoroscopy time, percutaneous needle access attempts, complications, and additional procedures were significantly lower in the rehearsal group (184.8 vs. 365.7 s, p < 0.001; 1.9 vs. 3.6 attempts, p < 0.001; 1 vs. 5, p < 0.001; and 1 vs. 5, p < 0.001, respectively). There were no differences in stone free rates, mean patient age, body mass index, or stone size between the two groups.

CONCLUSION

This study demonstrates that patient-specific procedural rehearsal is effective reducing the experience curve for a complex endourological procedure, resulting in improved surgical performance and patient outcomes.

Is it necessary to have a guidewire down through the ureter during mini percutaneous nephrolithotomy? Single-centre experience with 1052 cases

OBJECTIVES

In this study, it is aimed to identify the rate of successful placement of a guidewire down through the ureter during PNL and to compare the outcomes of different locations of guidewires in the collecting system following renal puncture in terms of success and complications rates.

PATIENTS AND METHODS

Data of 1052 patients who underwent miniPNL in our institution between January 2014 and November 2020 were analysed. Patients were divided into three groups. Group I consisted of patients with the guidewire coiled within the punctured calyx, group II consisted of patients with the guidewire reaching the renal pelvis and group III consisted of patients with the guidewire passed down through the ureter. The groups were compared for successful tract creation and complication rates.

RESULTS

There were 303 (28.8%) patients in group I, 330 (31.4%) patients in group II and 419 (39.8%) patients in group III. Successful tract dilation at the first attempt was established in 298 (94.7%) patients in group I, 328 (99.4%) patients in group II and in all of the 419 (100%) patients in group III. Successful tract creation was established in a second attempt in all of the patients failed in the first attempt. The groups were similar for stone-free and complication rates.

CONCLUSIONS

Placement of guidewire down through the ureter could not be established in more than 60% of the cases. Location of guidewire prior to dilation did not affect the outcomes. Therefore, we suggest to proceed with tract creation even when the guidewire coils within the punctured calyx.